Graph Coloring · Easy problem

Five committees $A, B, C, D, E$ meet weekly. Pairs of committees that share at least one member cannot meet in the same time slot. The shared-member pairs are: $A\&B$, $A\&C$, $B\&C$, $A\&D$, $B\&D$, and $C\&E$. What is the fewest time slots needed so that no two conflicting committees share one?